A link level flow control technique implements a "pull frame" transmission
model in a Fibre Channel network. In one embodiment, frames remain in a
first Fibre Channel device until they are requested by a second Fibre
Channel device, wherein the second Fibre Channel device does not issue a
request unless conditions are such that it can immediately transmit the
frame toward its target destination. In another embodiment, a Fibre
Channel device provides hardware messaging capability to support the pull
model. In yet another embodiment, multiple Fibre Channel devices in
accordance with the invention may be coupled to provide high port-count
Fibre Channel switches.